We have previously isolated a number of human colostrum whey glycoproteins and two glycoprotein preparations from human milk whey that had L. bifidus growth promoting activities. One of these milk glycoproteins was inhomogeneous, and one of the goals of this project is to separate its components in a homogeneous form. Another goal is to prepare antisera to the colostrum and milk glycoproteins and to examine the immunochemical relationships among them. Moreover, the antisera will be used to quantitate the glycoproteins in the milks of a number of individuals to learn their levels therein and their variation from one individual to another. Thirdly, human kappa-casein will be isolated, and its similarity or lack thereof to the whey acid glycoproteins will be established immunochemically and by chemical-physical means.